man im so sick of seeing this error! its happened to me a few times on my old pc, but this is the first time its happened on this one i have now, in the past i would just format the HD but this isnt even POSSIBLE on this error. But thats besides the point as i dont want to format the HD as ive got a hell of alot of stuff on it that i need, ive looked at this thread; http://www.techspot.com/vb/topic54182.html and read through it all, i downloaded knoppix and i dont even know how to use it, it wont let me do anything when it boots up. just tells me to enter a prompt and nothing i typed in worked, so thats a bit useless as of yet. when i use the XP disc it loads up, and stops when i choose anything, i.e. Repair, Recovery Console, Format etc..... the error says; ntfs.sys - address f84f01fc bus at f84e3000, Datestamp 41107eea the strange thing about it though is the fact that the hard drive im using doesent have windows installed on it, its a secondary hard drive for my PC, its an 80Gb HD and its along side my 200Gb HD and my windows (XP media center) is on the 200 which is partitoned into 120 and 80, and windows is on the 120 section. i dont really know too much about file systems or anything on the hard drives, but when i take the 80gb one out, the pc runs fine, but when i plug it in, the blue screen pops up. ive tried allsorts of different combinations of what goes where and still nothing. so any help would be much appreciated! thanks alot.